Highly accurate and high sample rate linear and rotational position encoders in the servo control loops of precision industrial machines can significantly improve machine accuracy and speed. Such improvements may be achieved by providing higher bandwidth position and velocity feedback, (i.e., higher position sample rate), and by eliminating position errors associated with wear, flexure and looseness in mechanical linkages (e.g., gears, levers and cams).
Optical multitrack absolute encoders (e.g., with binary digital Gray code scales) are often dismissed in favor of single-track approaches due to the possibility of measurement errors arising from imperfect alignment of readout mechanisms with respect to the measurement scale. However, absolute encoders in general have potential advantages of improved accuracy and machine operator safety.
The present disclosure relates to improved multitrack optical absolute position encoding systems and methods. As will become apparent, the systems and methods disclosed herein may significantly reduce position error and at the same time provide higher measurement sample rates.